Gold pan



July 2', 1957 B. A. KREss 2,797,809

` VGOLD PAN l Filed June 25; 1954 :e sheets-sheet 2 IN1/Emol; BRI/6E A. KRESS Arta/tuff Kress; nwistiigldand, assigner @rime-half to Frank J'."Br'em'eling, Clarkston,` Wash.

My invention'relates t'onew'andnovel improvements in Vmining equipment and especially apper'tains to improvements 'in' minin'g pans which areused in Yth'e manual recovery of ore.

Conventionally, mining pans are used which have an wardly from the bottornfat an included angle of 40 to Yfiwrd tot a level ornear levelposition andtli'e bottom assumes the 40 to 45 degree angles of the sides. Such massive movement of the materials prevents the gold, for example, or other high specific gravity ore from classifying out under the difference in gravity. Such defect is multiplied by the conglomerate in the bottom of the tipped pan when the ore creeps along the slick bottom of the pan, causing loss of values in the finishing off step.

I have found that by decreasing the angle of the side wall to an included angle of 18 to 26, the recovery is appreciably increased and the nishing off step is speeded up, particularly when processing fine or llake gold.

Therefore, the primary object of my invention is to provide a pan which enables an increase in the value and proportion of the ore recovery and a decrease in the time expended to be obtained.

Underlying my improved pan construction is the known law of phyiscs that when an inert object is placed on an inclined plane, the sine of the angle denotes the portion of the objects weight pushing or bearing down the inclined surface. When the angle of the incline is 180 or level, the portion of the object pushing against the incline is 1.0000 or 100%, under gravitational law, while the portion of the object pushing down the incline is .0000 or zero as the incline is negative at this point. When the incline is 180, plus one minute, the object then becomes .00029. However, the increase will have little eiect upon the objects weight pushing down the incline, until the angle of the incline reaches 26 and 34 minutes, at which time the sine will equal .4472 and cosine will equal .8744. At this point, one-half of the weight of the object is pushing down the incline, while one-half is pushing against the incline. Such is seen in subtracting sine .4472 from cosine .8744. Therefore, the object is approaching overbalance and starts moving by gravity down the incline.

The sloping of the side Wall of my pan below 26 allows 34" of angle margin to the bottom of the pan when the side wall is held level and such sloping permits the separation thrusts, given to the pan, to operate in an effective manner.

In other words, I have based the construction of my pan on physical laws to determine the proper slopes of the side wall. First of all, it is to be recalled that the higher the specic gravity of a material particle is, then the more tendency to inertia it has when placed on a slight incline. Secondary, it is to be recalled that the ore.

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In conventional miningpans, `which have a side wall angled on the' order of `40 to 45 degrees to the hat botbom'` wall, th'e'steep sid'e wall, when tiltedv to a level or near level f-position; causes the bottom to assume sch s'tep'angleandprevehtsf the gold and/or other high specilicgravity lmetals from' classifying out 'by the dif- Another Vobject of my `invention is to provide `a Vremovabl'mesh-typetr'ap for trapping line ores land `to provide `means-lor mounting it over the bottom wall-.1

(The 'foregoingandancillary objects are attained by this invention, the best known fornsv of which aredescribed in thefollowing-description and illustrated'in the accompanying--drawings, wherein;-

Figure 1 is a side elevational view, partly in section, of a pan, constructed in accordance with my invention.

Figure 2 is an enlarged top plan view of the pan.

Figure 3 is a detailed sectional view taken on line 3-3 of Figure 2.

Figure 4 is a perspective view of the fastening means for the removable bottom.

Figure 5 is a detailed sectional view taken on line 5 5 of Figure 2.

Figure 6 is a side elevational view, partly in section, of the pan, without the bottom insert.

Figure 7 is a view similar to Figure 6 of a smaller size pan.

Figure 8 is a view similar to Figure 6 of a smaller size pan.

Figure 9 is a view similar to Figure 6 of a smaller size pan, and,

Figure 10 is a diagrammatic showing of the angles of the side walls of the pans.

In Figures 69, four different sizes of a mining pan, constructed in accordance with my invention, are illustrated. The pan 10 in Figure 6 is the large size and has a bottom wall 12 and an upwardly and outwardly sloping side wall 16. The side wall is sloped 26 relative to the bottom wall. Such angular slope allows 34 minutes of angle margin to the bottom 12 of the pan when the sides are held exactly level and permits the separation thrusts to operate when separating, for example, black sand from gold. The diameter of the bottom wall is 9 inches and the overall diameter of the pan is approximately 19 inches, while the depth of the pan at its center is 21/2 inches.

In Figure 7 a smaller size pan 18 is shown, wherein the side wall 20 slopes at an angle of 221/2 t'o the bottom wall 22, and is of a diameter of approximately 8 inches. This pan 18 constitutes a decided improvement over bateas and horn-spoons, which are regularly used at mines, mills, reduction works, etc. The pan 26 of Figure 8 is similar to the pan 18 except that the diameter of the bottom wall 28 is 6" and the pan is otherwise smaller in size.

In Figure 9, the small size pan 30 is shown, which pan is ideal for testing small quantities of ore by assayers. The pan 30 has a bottom wall 32 of a diameter of 4". The side wall 36 of the pan 30 slopes at an angle of 18 relative to the bottom wall.

Figure 10 shows the angular range of the side Walls,

the maximum being 26 and the minimum 18, so that the side walls slope, dependent upon the size 4of the pan, in an included angular range of 18 to 26 relative to the at bottom walls.

In Figures 1-5, the pan 10 is shownhindetail and the bottom ore trap insert construction is clearly shown, such construction being similar for all sizes of pans. The side wall 16 is formed adjacent the bottom wall with equidistantly circumferentially spaced vertical openings which receive the shanks of the bolts 40. A circular mesh screen 42 has a metallic rim 44 secured thereto, the outer peripheral edge 46 of the rim being beveled on a 26 bevel to abut tightly against the inside juncture of the bottom wall and the side wall of the pan. The rim ts on the bottom wall and the screen 42 over- "lies the bottom wall to form an ore trap.

Angle clamps 48 are provided and are bent at a 26 angle to provide a side portion 50 and a bottom portion 52. The bottom portions 52 overlie the rim and the side portions 50 lie on the inside of the side wall. The side portions 50 are apertured to receive the shanks of the bolts with the heads thereof engaging the side portions. Wing nuts 54 are`threaded onto the extending threaded ends of the Shanks of the bolts. Under the mesh screen a canvas or other matting material can be placed and held in position by having its edges clamped between the rim and the bottom wall. Such matting provides an ore trap in trapping fine ore.

It is believed that the use and advantages of the placer be realized as come within the purview of the appended claim.

Having described the invention what is claimed as new is:

A mining pan comprising a ilat bottom wall and a side wall sloping upwardly and outwardly from the bottom wall at an angle of from eighteen degrees to twentysix degrees, a mesh screen positioned upon said bottom wall, a ring overlying the peripheral portion of said screen and bearing against the lower portion of said side wall, means provided for detachably connecting said ring to said side wall, said means including angle straps each having a side section and a bottom section, said sections being disposed at an angle complementary to the angular relation of the side Wall to the bottom wall and fasteners extending through the side wall and side sections to hold said straps in position, said ring having a beveled outer peripheral portion complementary `to said side wall.

References Cited in the le of this patent UNITED STATES PATENTS 585,989 Sletcher `uly 6, 1897 799,059 Johansen Sept. 12, 1905 865,178 Hardwick Sept. 3, 1907 

